President Biden announced another $8 billion in aid to Ukraine in a bid to circumvent a drawdown expiration deadline just one day after Russian President Vladimir Putin threatened to change the Kremlin's rules when it comes to its nuclear doctrine.

The Russian president said an attack on Russia using conventional weapons supported by a nuclear state may trigger a nuclear response.

U.S. President Joe Biden announced more than $8 billion in military assistance for Ukraine on Thursday to help Kyiv "win this war" against Russian invaders, using a visit by President Volodymyr Zelenskiy to make a major commitment.

North Korea, which has been accused of illegally supplying weapons to Russia, said on Sunday that U.S. military aid worth $8 billion to Ukraine is "an incredible mistake" and playing with fire against nuclear superpower Russia.

North Korea, which is accused of illegally supplying weapons to Russia, said on Sunday that US military aid to Ukraine worth US$8 billion is an "incredible mistake" and playing with fire against nuclear-armed Russia.